| 时间 | 值 | 世界排名 |
|---|---|---|
| 2016 | 4 | 100 |
| 2015 | 4.1 | 96 |
| 2014 | 4.1 | 96 |
| 2013 | 5.2 | 93 |
| 2012 | 5.7 | 89 |
| 2011 | 7.6 | 88 |
| 2010 | 1.2 | 117 |
| 2009 | 1.9 | 111 |
| 2008 | 2.2 | 110 |
| 2007 | 2.1 | 110 |
| 2006 | 2 | 109 |
| 2005 | 2.1 | 108 |
| 2004 | 0.6 | 129 |
| 2003 | 1.9 | 115 |
| 2002 | 33.2 | 74 |
| 2001 | 51.9 | 69 |
| 2000 | 33.1 | 78 |
| 1999 | 68 | 63 |
| 1998 | 48 | 70 |
| 1997 | 82.6 | 60 |
| 1996 | 116.6 | 49 |
| 1995 | 99.8 | 56 |
| 1994 | 213.8 | 34 |
| 1993 | 153.2 | 38 |
| 1992 | 174.4 | 34 |
| 1991 | 132.2 | 36 |
| 1990 | 112.5 | 44 |
| 1989 | 161.4 | 34 |
| 1988 | 115.2 | 39 |
| 1987 | 117.9 | 37 |
| 1986 | 98.9 | 39 |